What fraction of numbers 1 to 30 is prime?

Simply add up the primes - those numbers other than 1 whose only factors are 1 and themselves. 2,3,5,7,11,13,17,19,23,29 are all the primes from 1 to 30. There are 10 of them, and the set of integers from 1 to 30 encompasses 30 numbers, so 1/3 of the integers from 1 to 30 are prime. Technically there are infinite NUMBERS between 1 and 30 (0.1, 9.57, 0.000001, ...) but only 30 integers (1,2,3, ...). If the question is phrased with the Word "numbers" and not "integers" then the answer should technically be 10 primes divided by infinite numbers, and anything over infinity is 0, so your answer would be 0. So answer either 1/3 or 0; if you haven't really talked about infinity then it is probably 1/3 they are looking for.